How to create an auto lookup without
writing code where Field 2 lookup is based on Field 1 Value?

In order to achieve
this create a relationship in the related table but make sure Field 1 is the
first relation in the relationship and Field 2 is the second relation. This can
be done by actually creating Field 2 relation before Field 1.

How
to add a new Field in Managerial Hierarchy (Workflow Approval Limits)?

In order to add a new
field in the managerial hierarchy either create a new HierarchyProvider or use
WorkflowLimitHierarchyProvider class and add new fields in it. Check the new method of
WorkflowLimitHierarchyProvider to get an
overview.